Thread inspection apparatus



y 2, 1940- A. H. BURKHOLDER 2,206,833

THREAD INSPECTION APPARATUS Filed Oct. 26, 1937 FIG. 2

3nventor F153 I I ALDEN HBURKHOLDER Gttrneg Patented July 2, 1940 THREADINSPECTION APPARATUS Alden H. Burkholder, Cleveland, Ohio, assignor toIndustrial Rayon Corporation, Cleveland, Ohio, a corporation of DelawareApplication October.26, 1937, Serial No. 171,158

6 Claims.

This invention relates to a thread inspection apparatus and moreparticularly to apparatus for detecting irregularities in a continuouslyrunning thread.

While the apparatus may be utilized to inspect thread of either naturalor synthetic origin, it is especially useful for inspecting syntheticthreads, such as artificial silk thread. An inspection may be made of asynthetic thread not only to determine the quality of the particularthread but for the additional and sometimes more important purpose ofdetermining whether or not the machine which produced that thread isoperating satisfactorily. For example, if the openings of a spinneretbecome clogged, the broken filaments which necessarily result will beinstantly shown by a thread inspection apparatus such as that oi theinvention. Likewise, it the spool has been improperly wound due to somedefect in the thread traverse mechanism, the occurrence of such faultsin the winding may be detected by the apparatus of the invention.

By making freirregularity without causing damage to the thread, asotherwise the nature of the irregularity cannot be determined. Thus, ifa positive pull is exerted upon the thread and if an irregularity occurssuch as to stop movement of the thread,

the positive pull not only will break the thread but will so mutilatethe thread where the irregularity occurred that the-character of theirregularity will not be ascertainable. For these reasons, it isdesirable that movement of the thread be arrested, but the thread itselfleft unbroken;

A feature of the present invention is the provision of an apparatuswhich will exert an impositive drawing force upon the thread. Inasmuchas the force thus exerted upon the thread is of a yielding nature, themotion of the thread may be checked without causing thread breakage andwithoutdestroying the identity of the thread irregularity. This makes itpossible to examine the thread to determine the precise nature of theimperfection in the thread.

A preferred structural embodiment of the section on'line 2-2 of Figureview on the line 33 of Figure scale.

1; Figure 3 is a.

1 man enlarged The thread 5 which is to be inspected ordinarily will becontained upon spools or bobbins, such as the bobbins 6 illustrated,from which the thread may be unwound by drawing it in an axial directionfrom the spool or bobbin. Such spools or n bobbins may be locatedremovably upon pins l projecting from the same side of a horizontal beam3 carried by uprights t of the apparatus framework. In the apparatusillustrated the pins "l' are parallel and lie in a horizontal plane al-10 though this is not essential. The thread-drawing device ill whichserves to pull the threads on the bobbins 6 preferably is located at theopposite end of the framework from the projecting pins i.

The illustrated thread-drawing device it comprises a tube it having itsentrance end i2 preferably flared and located at about the same horizontal level as the axes of bobbins 6. Tube l l is supported by beingfixed to a centrally disposed upright support It or the apparatusframework and to a horizontal beam It upon the upper end of upright l3.Fluid, such as air, under pressure is directed into the upper flared endof tube H from a nozzle l6. Petcock l! in the 2d supply pipe it controlsthe admission of fluid to nozzle it. -Supply pipe i8 is supported byattachment to upright l3 and beam it. By 10- cating nozzle it on theside of tube I l which is away from the bobbins 6, the'entrance of thethread from the spoolslnto the tube will not be obstructed.

Supply pipe It! may be connected-to any suitable source of fluid underpressure such as com-' pressed air. It, is only necessary that the fluidas be under sufllclent pressure so that when petcock l'l is-opened andfluid is'forced to flow through tube II, the current will be strongenough .to exert a drawing action upon the thread. By controlling theadmission of fluid 40 into nozzle II, the thread may be drawn ofl?bobbins 6 at as great a rate as is desired. It has been found that thedrawing force exerted by the current of fluid flowing through tube I Iis dependent to some degree upon the length of the 5 tube, and for thisreason it is desirable that the tube ll be as long as is feasible.

At its lower end tube ll extends into a col lecting receptacle, such asbasket l9. while this basket may be of any suitable size, it has beenfound desirable that it be as large as is convenient, since greaterassurance is thereby had that the thread delivered into the basket willbe retained. therein. If the collecting basket is of moderate. size, itmaybe necessary to utilize as 35 velocity, likewise loses its carryingforce, the

thread will be deposited within the "collecting basket I9.

In the illustrated embodiment each thread 5 traveling from a bobbin 6 tothe thread-drawing means Ill passes through a pair of stripper elements2| and 22, being in the illustrated embodiment means for detectingirregularities in the thread. -These stripper elements are provided withslots 23 and 24, respectively, opening at one end of each element, thewidth of t e slots being but slightly greater than the thickness of thethread. Stripper elements 2| are mountedso that their slots 23 arevertical while stripperelements 22 are mounted so that their slots 24are horizontal and, as is shown in Figure 3, slots 23 and 24 of eachassociated pair of stripper elements 2| and 22 cross each other. Bydisposing the stripper elements 2| and 22 of each pair at right anglesto each other in this manner, the slot of the one stripper elementserves as a guide for the other stripper element. Furthermore, greaterassurance is had that the slightest thread irregularity will bedetected, since the crossing of the stripper elements results in allsides of the thread being acted upon.

The vertically disposed stripper elements 2| are secured by screws 25along a horizontal beam 26 carried upon uprights 21 of the apparatusframework. It is preferable that each stripper element 2| be locateddirectly in line with the corresponding pin 1. Stripper elements 22 areshown as carried by blocks 28 fastened upon the upper side of horizontalbeam 26, and are preferably secured by screws 29 to the carrying blocks28 in such manner that the stripper elements 22 are pivotally mounted.To retain the stripper elements 22 in a horizontal position about screws29, stop pins 30 carried by the supporting blocks 28 preferably areprovided.

The uprights 9 and 21 and the end uprights |3 are secured tolongitudinally extending parallel side rails 32 and 33. These rails areretained in spaced-apart relation by the end rails 34 and 35. Thecentrally disposed vertical upright l3, to which tube II and supply pipel8 are secured, is fastened both to end rail 34 and to the horizontalbeam I4. Basket l9 may be positioned upon the side rails 32 and 33.

In putting the apparatus into use, the petcock I6 is first turned on.Thread-from one of the bobbins 6 is then drawn from the bobbin and isdelivered to the entrance end |2 of tube The stripper element 22 throughwhich the thread is to pass is next turned to an upright position aboutits pivot .screw 29 and the thread is located in the slot 24. Stripperelement 22 is then turned about its pivot screw'29 to a horizontalposition, the thread being so guided in slot 24 that it enters slot '23of stripper element 2|. From this point onward the thread will continueto be drawn oii bobbin B and through the slots 23 and 24 until somethread"irregularity prevents passage of the thread through the stripperelements oruntil some defect in the winding upon bobbin 6 preventsthethread from unwinding...

' parent.

Inasmuch as the thread-collecting device l0 functions to exert ayieldable drawing force upon the threads passing from bobbins 6, in theevent that an irregularity in one of the threads causes movement of thatthread to be checked by the 5 stripper elements 2| and 22 the threadwill not be broken. Moreover, due to the yieldable character of theforce which the fluid passing into the tube exerts upon thethread, thethread will be stopped so that the irregularity in the thread remains atits point of occurrence in the thread. In this manner it is possible foran attendant to examine the thread and determine the precise nature ofthe defect which caused the thread to stop.

For example, if stoppage of the thread was caused by a snarl in thethread, the snarl will remain in the thread and can be detected as sucha defect, whereas if a positive drawing force had been exerted upon thethread and the thread ,had consequently been broken, it would beimpossible to tell whether the defect had been caused by a brokenfilament, a loop or a snarl. In like manner, if the thread is stoppedbecause of an underwind upon the bobbin, since the force exerted uponthe thread to unwind it is of a yieldable nature, the character of theunderwind will not be affected and it will be possible to determine thecause of the underwinding, as whether the underwind is caused by adefeet in the manner of winding the thread upon thebobbin or is due tothe washing over of the thread turns during subsequent processing of thebobbin;

Instead of the'stripper elements 2| and 22 it is possible for anattendant to let the thread pass between his fingers on its way from.the winding bobbin 6 to the thread-drawing device l0. Because of theyieldable nature of .the drawing force upon the thread the operator mayinstantly check the motion of the thread for the purpose of determiningits quality at a particular point. When he releases the thread it willrapidly pass through the fingers until some point further along thethread is reached for inspection. Since the thread-drawing means In isexerting a constant force upon the thread, the attendant may devote hisentire attention to inspection of the thread before him and is not concerned with setting the thread in motion between points of inspection,or with possible breakage of the thread.

While the apparatus has been illustrated as a means for the inspectionof thread which has been wound upon a conventional bobbin, it may beapplied to an apparatus which is continuously producing thread. In suchan application of the invention, the thread 5 may be one that is beingcontinuously produced, as by a machine of the type disclosed in theapplication of Walter F. Knebusch and Alden H. Burkholder, Serial *No.7,114, filed on February 18, 1935. In such faulty character and shouldbe passed to waste.

Other applications of the invention will be ap- Various' modificationsof the apparatus shown will occur to those skilled in the art. Forexample, instead of arranging the parts of the appahorizontal path, theymay be so arranged that other respects to suit different situations tobest advantage.

It is intended that the patent shall cover, by suitable expression inthe appended claims, whatever features of patentable novelty reside inthe invention.

What is claimed is:

1. Thread inspection apparatus comprising a source-of thread ofsubstantially continuous length ;-1neans for detecting irregularities inthe thread through which is passed thread from said source, said meansarresting motion of the-thread in the event an irregularity isencountered; and

means for subjecting the thread to a fluid force which impositivelydraws the thread through said detecting means in such manner that thethread remains unbroken even though its motion is arrested.

2. Thread inspection apparatus comprising a source of thread ofsubstantially continuous length, a thread-drawing device comprising atubular passageway, means for inducing a current flow through saidtubular passageway from one end thereof to the other whereby threadbrought to the entrance end will be carried throughout the length of thepassageway, and means between the source of thread and saidthread-drawing device for detecting irregularities in the thread.

3. Thread inspection apparatus comprising a source of thread ofsubstantially continuous length, a thread-drawing device comprising atubular passageway, means for inducing a current flow through saidtubular passageway from one end thereof to the other whereby threadbrought to the entrance end will be carried throughout the length of thepassageway, and means between the source of thread and saidthread-drawing device for arresting, movement of the thread upon theoccurrence of an irregularity.

4. Thread inspection apparatus comprising a source of thread ofsubstantially continuous length, means for drawing the thread from saidsource comprising a tubular passageway through which is induced acurrent of fluid tending to carry thread through said passageway, and,dis

posed between said source of thread and said drawing means, a memberhaving an opening through which the thread is passed, said opening beingsubstantially the size of the thread so that irregularities in thethread will be caught and motion of the thread arrested.

5. Thread inspection apparatus comprising a source of. thread ofsubstantially continuous length, means for drawing the thread from saidsource comprising an elongated tubular passageway through which isinduced a current of fluid tending to carry thread through saidpassageway, and, disposed between said-source of thread and said drawingmeans, a pair of slotted stripper elements through which the threadpasses, said stripper elements being disposed with their slots crossingeach other so that irregularities in the thread will be caught andmotion of the thread arrested.

6. Apparatus comprising a plurality of sources of thread; a commontubular passageway so constructed as to permit thread from said sourcesto pass therethrough, said tubular passageway being of relatively smallcross-section and of relatively great length as compared with saidcrosssection; means disposed at the entrance end of said tubularpassageway for introducing thereinto a jet of fluid directed toward thedischarge end of said tubular passageway; means disposed between saidsources of thread and said tubular passageway for detectingirregularities in the thread; and, disposed at the discharge end of saidtubular passageway, means for collecting the thread issuing from saidtubular passageway.

ALDEN H. BURKHOLDER,

